UA study: Diesel exhaust here linked to childhood wheezing

Davis Bilingual Magnet School is near one source of diesel
pollution - Interstate 10. Other areas with high diesel emissions
were along I-19 and Aviation Parkway.

BENJIE SANDERS / ARIZONA DAILY STAR

Infants and very young children in Tucson exposed to high levels
of vehicle diesel pollution are more likely than other kids to
suffer from early childhood wheezing, a potential asthma
indicator.

That's the finding of a new University of Arizona study, the
first in Tucson to link vehicle air pollution to respiratory
problems in children.

Based on a study of 700 people, it found a connection between
the diesel exposures and what's known as "transient wheezing,"
which starts in infancy and goes away at about age 5 or 6, said
Paloma Beamer, an assistant UA professor of environmental health
sciences and a principal investigator and one of six researchers on
the study.

The study compared children from census tracts with the highest
diesel emissions, including areas along Interstates 10 and 19 and
the Aviation Parkway, with kids in the entire metro area. The
researchers got the diesel data from the Environmental Protection
Agency. The main sources of the diesel emissions were trucks, buses
and trains.

The study found that children with higher diesel exposure were 1
1/2 times more likely than other kids to have a respiratory illness
that included wheezing in their first three years of life. They
were nearly twice as likely to have transient wheezing in early
childhood that went away by age 6, Beamer said.

In short, young kids who wheeze "are more likely to have diesel
exposure than those who don't wheeze," said a second UA researcher
who worked on the study, Anne Wright, a professor of
pediatrics.

Wright is also a founder and a co-principal investigator of a
much broader research effort known as the Tucson Children's
Respiratory Study from which the kids studied in the wheezing
research were drawn. The larger respiratory study has monitored the
health of a target group of Tucsonans since they were newborns back
in 1980.

Wheezing is a constriction in the lungs that sounds like
whistling and makes it hard for air to move in and out of the
lungs. A majority of children have wheezing problems in the first
few years of their lives due to viral infections, but for most of
them it goes away later, Wright said.

Later in life, wheezing is more common among allergy sufferers
and is a leading symptom of asthma for older people. For younger
kids, wheezing patterns are more complicated, Wright said. A lot of
kids who get asthma later in life will wheeze in their early years,
but most kids who wheeze in their early years do not go on to have
asthma, she said.

The association between diesel exhaust exposure and transient
wheezing was stronger in kids whose parents don't smoke, Beamer
said. With kids of smokers, the smoking is a much bigger factor
than the diesel emissions affecting the kids' respiratory
health.

Kids of mothers without at least a high school diploma also had
a higher chance of being affected by the diesel particulate
emissions, she said.

"Those households may already be under other types of
socio-economic stress," Beamer said.

Numerous university studies in the Los Angeles area have in the
past decade linked a variety of health problems to living near and
breathing fumes from freeways. They include respiratory ailments,
autism, premature births and hardening of the arteries.

But Beamer said that as far as Tucson goes, it is too early to
say whether people with kids or who expect to have kids should
avoid living near freeways.

"Is this something that deserves more inspection? Yes," Beamer
said. "But I would be far more concerned about a smoker living in
my household than living close to the freeway."

The researchers' long-term goal is to find ways for parents to
intervene at the home level to protect their kids if they live in a
neighborhood near a freeway, she said.

"If you are a mother living near the freeway for a reason, are
there things you can do to prevent childhood exposures during
critical periods of development?"

The researchers are also going to see if any kinds of public
policies need changing to protect such children.

The preliminary study, which has not yet been published, was
funded with a $40,000 grant from the UA's Southwest Environmental
Health Sciences Center.

Beamer and her colleagues have recently started a much more
expansive, $670,000 project to try to determine if a relationship
exists between exposures to diesel pollutants in the Tucson area
and lung and immune-system development and allergies. The National
Institutes of Health is financing this ongoing study.